Needle bed translation control assembly

ABSTRACT

A needle bed translation control assembly for a home knitting machine comprising a mounting bracket carried by the needle bed, a dial cam with a cam groove therein, a link member fixed to the frame of the machine having a pin thereon adapted to ride within said groove, rotation of said dial cam resulting in predetermined translational movement of said needle bed.

United States Patent 1 1 Rogers et al.

[ 1 NEEDLE BED TRANSLATION CONTROL ASSEMBLY [75] Inventors: Howard David Rogers, Westfield;

John Charles Cariddi, Saddlebrook;

Henry Schaeflern, Pittstown, all of NJ.

[73] Assignee: The Singer Company, New York,

[22] Filed: Aug. 30, 1973 [21] Appl. No.: 393,083

[52] US. Cl. 66/69 [51] Int. Cl. D04b 7/00, D04b 7/20 [58] Field of Search 66/69, 60 H, 60, 64

[56] References Cited UNITED STATES PATENTS 943,921 12/1909 Dubied et al. 66/69 14 1 Sept. 17, 1974 1,072,856 9/1973 Kellneretal 66/69 1,984,991 12/1934 Robuczynski. 66/69 X 2,284,167 5/1942 Ralston 66/69 3,052,108 9/1962 Lumsdcn 66/69 3,477,254 11/1969 Comas .1 66/69 Primary ExaminerRona1d Feldbaum Attorney, Agent, or Firm-Marsha11 J. Breen; Chester A. Williams, Jr.; Joel Halpcrn [57] ABSTRACT A needle bed translation control assembly for a home knitting machine comprising a mounting bracket carried by the needle bed, a dial cam with a cam groove therein, a link member fixed to the frame of the machine having a pin thereon adapted toride within said groove, rotation of said dial cam resulting in predetermined translational movement of said needle bed.

5 Claims, 3 Drawing Figures PATENTEU 5P! 7.4

FIG. 3

NEEDLE BED TRANSLATION CONTROL ASSEMBLY BACKGROUND OF THE INVENTION Hand or home knitting machines may be classified in two categories, i.e. single needle bed and those having front and back needle beds or at least the capacity for the coupling of a second needle bed to a permanent single or back bed. Naturally, the versatility of the machine is increased by the addition of the second needle bed since a greater variety of stitch patterns and knitted fabrics may be thus produced. However, in order to fully utilize both needle beds it is essential that the machine provide for lateral translation of the front needle bed relative to the back bed so as to permit different positions of needle alignment between the beds and a variety of needle working combinations.

Sideways translation of the front bed serves to either align or offset the needles thereof with respect to those carried by the back bed. When aligned the translated or racked position of the front bed may be referred to as full position or full pitch and when offset the position may be referred to as half position or half pitch. In addition to providing for translation of the front needle bed so as to achieve full or half pitch position it is customary to allow for additional incremental translation of the front bed in order to make possible further stitch variations. Generally, the total amount of sideways movement found necessary has been approximately one and one half inches.

It has been usual to incorporate lever or similar handle means below the frame of the machine within the grasp of the operator to facilitate racking or translation of the needle bed. Various systems for effecting translation of the needle bed have been employed. For example, Passap, a Swiss manufacturer of home knitting machines utilizes a pair of bevel gears arranged such that a manually operable handle is connected to one of the gears whereas the second gear is carried by a shaft also having a worm gear which meshes with a third gear cooperable with a rack for imparting translational movement to the needle bed. Silver Seiko Co., Ltd., a Japanese manufacturer of such machines, on their Model No. 321 home knitting machine utilizes a rack and pinion. Superba S.A., a French manufacturer of home knitting machines, employes a die cast member in which a pair of ball elements are positioned in one of a series of detents and are maintained in seated position by a leaf spring.

The foregoing prior art devices for racking of the needle bed have been found to perform in less than an optimium manner for various reasons. Complaints from operators are frequently directed to the clumsiness of the manually operable handle means, to the fact that once set in a selected position the needle bed may be too easily dislodged, or that there is too much looseness in the linkage system whereby the selected position is not as accurate as may be desired.

SUMMARY OF THE INVENTION It is one object of the present invention to provide a needle bed translation or racking control assembly for a home knitting machine which is easily manipulable and difficult to accidentally dislodge from the selected position.

It is another object of the present invention to provide a needle bed translation or racking control assembly for a home knitting machine which is capable of accurately positioning the needle bed in the selected racked position.

Other objects and advantages of the aforesaid control assembly will become readily apparent upon a reading of the following description of the invention.

According to the present invention there is provided a needle bed translation control assembly for a home knitting machine, comprising a mounting bracket adapted to be secured fixedly to the front needle bed of the machine, a dial cam carried by said bracket rotatable about an axis substantially perpendicular to the longitudinal axis of said needle bed, and a link member secured to the frame of the machine in fixed relation thereto, said dial cam being provided with a noncircular groove in a face thereof, and said link member having a pin thereon adapted to ride within said groove, whereby rotation of said dial cam a predetermined amount results in a correspondingly predetermined linear movement of saidneedle bed.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully comprehended it will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is an exploded perspective view of a preferred embodiment of the racking control assembly of the invention; and

FIG. 2 is a side elevation view in cross section of the assembly shown in FIG. 1; and

FIG. 3 is a plan view of the dial cam showing the relationship between the curvature of the cam groove and the linear translational limit for the needle bed.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2 of the drawings there is shown a home knitting machine 10 depicted in phantom because the details of such machine are standard and thus need not be described in any detail. The machine is constructed with a back bed main base structure, as is well known, which is furnished with a front needle bed supporting bracket adapted to permit reciprocatory or translational movement of the front needle bed thereon. Front needle bed 12 includes a frame 11 (a portion of which is shown). A second back needle bed 13 may also be provided and is shown in phantom since details thereof have no relevance to the present invention. On some machines the front or back needle bed may be an optional accessory.

Secured to the frame of the front bed is the needle bed racking or translational control assembly 14. This assembly comprises a mounting bracket 15 which is fixedly secured desirably to the underside of the needle bed by suitable fastening means such as machine screws 16 one of which is shown. The mounting bracket is preferably formed with a bight portion 15a and a pair of spaced legs 15b and 15c. The upper leg is desirably configured to closely engage a portion of the needle bed so as to be rigidly secured thereto as by machine screw 16 already mentioned. The actual shape of the mounting bracket is not critical and it is contemplated that where the frame of the needle bed is formed'so as to present a horizontal surface it is possible to utilize a mounting bracket which is substantially planar.

A centering pin 17 extends through the lower leg of the mounting bracket and carries thereon a dial cam 18 in which is formed a cam groove or track 19. The lower end of centering pin 17 is necked down as at 20 to receive a washer and locking element such as a spring clip 21 to retain the dial cam thereon. The other end of the centering pin may be formed with an enlarged head to insure retention of the pin on the mounting bracket. According to a preferred embodiment dial cam 18 is provided with a generally centrally located aperture within which an eccentric bushing 22 is positioned as by a slip-fit so as to permit rotation of said dial cam about said bushing. The eccentric bushing is dimensioned to receive centering pin 17 in a relatively snug fit. It is not critical, however, whether or not the v centering pin rotates together with the dial cam although for the sake of convenience the clearance between the pin and the bore of the eccentric bushing should be sufficiently great so as to permit ready disassembly of the dial cam from the mounting bracket. For example, it is conceivable that the original dial cam may be replaced by one which has been designed to provide for increased needle bed translation. In such event it is simply necessary to remove the original dial cam from the centering pin and to reassemble the unit with a new dial cam. This flexibility, although possible with the racking assembly of the invention, is not the presently preferred use.

As may be seen from FIG. 1, a selector lever 23 is mounted on the eccentric bushing for effectuating translation of the needle bed between the half pitch or half position and full position settings of the needle bed. This will be described hereafter in greater detail.

A link member 24 is secured fixedly at one end thereof to the frame of the machine and is provided adjacent the other end with a slot 25 therein. The slot is dimensioned to permit the centering pin 17 and eccentric bushing 22 to extend thereinto and to permit these elements to slide therewithin in the manner to be presently described. If desired the link may be formed in sections with the extension having the slot 25 therein being provided with smaller slots 26 through which fastening means such as machine screws 27 may extend to unite the separate sections of the link. Slots 26 may be employed to afford linear adjustment of the link length. Further, affixed to the link member is a cam follower 28 which, as illustrated, may take the form of a pin or stud. However, it will be understood that the cam follower may be a roller or the equivalent. The purpose the the cam follower is to ride within the cam groove 19 when dial cam 18 is rotated and thereby cause sideways or translational movement of the dial cam and the mounting bracket which carries same. Since the mounting bracket is fixedly secured to the front needle bed of the machine the needle bed is thus translated or racked a predetermined linear distance depending upon the degree of rotation of dial cam 18 and the curvature of cam groove 19 therein. When the dial cam is rotated and cam follower 28 rides within the cam groove centering pin 17 and the eccentric bushing surrounding same slide within slot 25 of link member 24, the slot arrangement thus permitting relative sideways or translational motion between the dial cam, mounting bracket and needle bed and the frame of the machine.

As stated above, means are provided for racking or translating the needle bed between the half pitch and the full pitch settings. According to the presently preferred embodiment this is accomplished through the use of the eccentric bushing 22 and the selector lever 23. As shown in FIG. 1, opposed portions of the exterior surface of the eccentric bushing are provided with flat surfaces 29 which are adapted to receive complementary surfaces on the selector lever. Spring means (not shown) may be provided to urge the handle portion of the selector lever into one of a pair of notches 30 formed in the mounting bracket. Thus, by depressing the selector lever and by rotating same the eccentric bushing is simultaneously rotated and the needle bed is caused to move sideways to the selected half pitch or full pitch setting.

As depicted in FIG. 1 the link member 24 may be provided with a series of detent notches 31 and the mounting bracket 15 may have a detent spring 32 attached thereto held in place by fastening means such as screw 33. The purpose of this arrangement, as is apparent, is to facilitate incremental translational movement of the needle bed. In each predetermined incremental setting detent spring 32 tends to retain the needle bed by being biased into one of the detent notches. It will, of course, be understood that the detent spring may be mounted elsewhere on the needle bed and the detent notches may be carried at a different location elsewhere on the frame of the machine so long as these elements are positioned to achieve the desired cooperative effect.

Referring to FIG. 3 of the drawings it will be observed that non-circular cam groove 19 has its loci ar ranged about the central aperture and axis a of the dial cam so as to provide for the desired translational movement of the link and thus of the needle bed as will be determined by the horizontal distance d between the end points b" and a. In designing the curvature of the groove it should be borne in mind that the relationship between such curvature and the total translational distance to be built into the cam may afford substantially equal linear translational distances per degree of dial cam rotation.

It will be understood that various changes in the details, materials, arrangements of parts, and operating conditions which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principles and scope of the invention.

Having thus set forth the nature of the invention, what is claimed herein is:

1. A needle bed translation control assembly for a home knitting machine, comprising a mounting bracket adapted to be secured fixedly to the front needle bed of the machine, a dial cam carried by said bracket rotatable about an axis substantially perpendicular to the longitudinal axis of said needle bed, and a link member secured to the frame of the machine in fixed relation thereto, said dial cam being provided with a noncircular groove in a face thereof, and said link member having a pin thereon adapted to ride within said groove, whereby rotation of said dial cam a predetermined amount results in a correspondingly predetermined linear movement of said needle bed.

2. A control assembly according to claim 1, wherein said groove is spiral and is formed in the upper face of said dial cam.

3. A control assembly according to claim 1, wherein a plurality of detent notches is provided on the said link member and a detent spring is carried by said bracket adapted to seat within successively located notches so through said slot to a point above the surface of said link member, selector lever means being carried by said eccentric bushing cooperable with a pair of notches on said bracket, whereby movement of said selector lever from one of said notches to the other effectuates rotation of said eccentric bushing and of said dial cam so as to move the needle bed between the half pitch and full pitch positions. 

1. A neelde bed translation control assembly for a home knitting machine, comprising a mounting bracket adapted to be secured fixedly to the front needle bed of the machine, a dial cam carried by said bracket rotatable about an axis substantially perpendicular to the longitudinal axis of said needle bed, and a link member secured to the frame of the machine in fixed relation thereto, said dial cam being provided with a non-circular groove in a face thereof, and said link member having a pin thereon adapted to ride within said groove, whereby rotation of said dial cam a predetermined amount results in a correspondingly predetermined linear movement of said needle bed.
 2. A control assembly according to claim 1, wherein said groove is spiral and is formed in the upper face of said dial cam.
 3. A control assembly according to claim 1, wherein a plurality of detent notches is provided on the said link member and a detent spring is carried by said bracket adapted to seat within successively located notches so as to permit the setting of said needle bed at any of a plurality of selected linear translated positions.
 4. A control assembly according to claim 1, wherein means are provided for moving said needle bed between half pitch and full pitch positions.
 5. A control assembly according to claim 4, wherein a longitudinally extending through slot is provided in said link member, said dial cam is mounted about an eccentric bushing having a portion thereof extending through said slot to a point above the surface of said link member, selector lever means being carried by said eccentric bushing cooperable with a pair of notches on said bracket, whereby movement of said selector lever from one of said notches to the other effectuates rotation of said eccentric bushing and of said dial cam so as to move the needle bed between the half pitch and full pitch positions. 